Variable condenser



1934- P. F. SCOFIELD 1,977,289

VARIABLE CONDENSER Filed 001;. 4, 1932 lNSULA T/ON INVENTOR,

HlL/P F. SCOF/ELD. B MW ATTORNEY Patented Oct. 16, 1934 VARIABLE CONDENSER Philip F. Scoileld, Palo Alto, Calif., assignor to Helnta a Kaufman, Ltd., San Francisco, Calif., a corporation of Nevada Application October 4, 1932, Serial No. 636,230

2 Claims. (Cl. 'IHZS) My invention relates to a variable condenser and, more particularly, to a'condenser which is operated by a worm gear drive. Y Among the objects of my invention are: 6 To provide a means for varying the capacity of large condensers: I To provide a worm gear for varying the capacity of a condenser:

To provide an irreversible gear drive for a va- 1 riable condenser:

And to provide means for taking up back-lash in a worm gear drive for variable condensers.

Referring to the drawing, showing a preferred embodiment of my invention:

Figure 1 is an end elevation, and- Figure 2 is a plan view thereof. A-pair offlshafts 1--1 having condenser plates 2 mounted thereon, are positioned within a frame 3 in such a manner that when the shafts are roo tated in frame bearings 4, the plates will interrod terminated at one end by ,a hand wheel 11,

and carrying a worm 12 solidly applied to the rod 85 at a' point where it will mesh with both of the gear sectors 7--'l.

The worm is meshed with the sectors so that a continuous progression of theworm over the entire sector will varythe interleaving of con- 40 denser plates from zero to maximum. It is also desirable to have the gears so cut as to be irreversible, that is, so that the weight of the plates will not turn the worm in any position. This Fastenedto each shaft, between the plates and saves counterbalancing of the plates and allows plates of heavy construction to be used, as is desirable in high powered radio transmitters.

To remove all back-lash, a tension spring 13 is attached to the upper angle of one sector by an upper spring stud l4, and to the lower angle of the other sector bya lower spring stud 15.

The stress thus applied to the sectors causes the sectors to bear against opposite sides of the threadof theworm l2, withsuflicient pressure to eliminate backlash throughout-thetravel cf the sectors. The opposing stresses cancel each other so that there is no additional thrust load placed on the worm shaft 10.

A worm drive as described will allow high gear reductions, and the amount of interleaving, and capacity, can be changed in small increments, thus providing delicacy of adjustment. The drive is ideally adapted for extremelylarge capacitors, where the plates may reach the size of 12 -by 12 inches, and the entire condenser made up of as many as plates. The irreversibility of the gear readily takes care of theunbalanced weights.

I claim:

1, A drive adapted to interleave condenser plates comprising a pair of shafts adapted to be rotated. on which said plates are mounted, a gear sector on each of said shafts, a common worm gear-meshing with each of said sectors, and re- 1 rotated, on which said plates are mounted, a, gear sector on each of said shafts, a common worm gear meshing with each of said sectors, and a spring under tension connecting said sectors,

said spring having one sector connection above the contact of worm and sector and the other seetor connection below said contact.

PHILIP r. scor'mm. 

